Clinical Features Of Autoimmune Encephalitis With Antibodies Against Contactin-associated Protein-like 2

ObjectiveTo characterize the clinical spectrum,laboratory results,radiological features,treatments,and prognoses of patients with antibodies against contactin-associated protein-like 2(CASPR2)which help to improve the understanding of this disease and avoid misdiagnosis.MethodsA retrospective cohort study of 13 patients with anti-CASPR2 encephalitis who were admitted to the People’s Hospital of Zhengzhou University from March 2015 to June 2019 was conducted.The demographics,clinical characteristics,laboratory results of cerebrospinal fluid and serum,radiological features of brain MRI and positron emission tomography-computed tomography(PET-CT),treatments and follow-up data were reviewed.Results1.Among 13 patients,5 were male and 8 were female.Median age at symptom onset was 28 years old,age ranged from 20 to 74 years old.2.Among 13 patients,5 patients had prodromal symptoms including 2 case for fever with headache,1 case of fever,1 case of poor appetite,1 case of palpitation.The initial symptoms included epilepsy(5 cases),abnormal mental behavior(2 cases),pain in the lower extremities(2 cases),muscle twitch(2 cases),sleep disorder(1 cases)and walking unstable(1 cases).Among 13 patients,69%(9 cases)patients had symptoms of limbic encephalitis,54%(7 cases)had autonomic dysfunction,54%(7 cases)had sleep disorder,46%(6 cases)had weight loss,31%(4 cases)had muscle twitch,31%(4 cases)had neuropathic pain and 15%(2 cases)had ataxia.3.62 percents of the patients had at least 3 of the following symptoms:encephalopathy(cognitive deficits or seizures),cerebellar dysfunction,peripheral nervous system hyperexcitability,dysautonomia,insomnia,neuropathic pain,or weight loss.4.All serum samples from the 13 patients were positive for anti-CASPR2 antibodies.11 patients were tested for autoantibodies in CSF,and 4 were positive.5.All patients underwent brain MRI scan and 3 patients had abnormal brain MRI which showed abnormal signal in hippocampus or temporal lobe.6 patients underwent positron emission tomography-computed tomography(PET-CT),and 3 patients showed abnormalities,which showed hypermetabolism in cerebral cortex or medial temporal lobe.6.Among 13 patients,only one patient had tumor which was thymoma.7.For 11 of 13 patients,follow-up was performed for at least a 6-month period.The average follow-up was 11 month.Of these,3 patients had recurrence.The clinical manifestations at the time of relapse were similar to those at the first episode.And immunotherapy for relapsed patients is effective.ConclusionThe main clinical manifestations of anti-CASPR2 encephalitis are encephalopathy(cognitive deficits or seizures),cerebellar dysfunction,peripheral nervous system hyperexcitability,dysautonomia,insomnia,neuropathic pain,and weight loss.Most patients can combine multiple clinical manifestations at the same time or in succession.Anti-CASPR2 encephalitis does not tend to be associated with tumors and has a good responds to immunotherapy.Patients with anti-CASPR2 encephalitis patients may have recurrence and immunotherapy for relapsed patients is effective.